Polycyclic ethers and an unexpected dearomatisation reaction during studies towards the bioactive alkaloid, perophoramidine. Issue 26 (28th June 2018)

• Record Type: Journal Article
• Authors: Johnston, Craig A.; Wilkie, Ross P.; Krauss, Helmut; Neal, Andrew R.; Slawin, Alexandra M.Z.; Lebl, Tomas; Westwood, Nicholas J.
• Is Part Of: Tetrahedron. Volume 74:Issue 26(2018)
• Page Start: 3339
• Page End: 3347
• Publication Date: 2018-06-28
• Subjects: Natural product -- Ring opening reaction -- Cyclic ether -- Dearomatisation; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2018.04.086
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: The bioactive alkaloid natural product perophoramidine and the related family of compounds known as the communesins have inspired the synthesis community for more than a decade. Many of the elegant approaches have required the synthesis of complex intermediates that have not always reacted in the expected manner. In this study we describe a series of cyclic ether-containing precursors that were prepared during our synthetic studies towards these natural products. Attempts to open the cyclic ether ring and trap the resulting stabilised carbocation with a carbon nucleophile ultimately led to the preparation of a diallyl-substituted all carbon quaternary centre. Subsequent attempts to differentiate between the two allyl groups resulted in a relatively clean transformation to an unexpected compound. Extensive structural characterisation, including small molecule X-ray crystallography, showed that a dearomatisation reaction had occurred. Graphical abstract: Image 1